[Ar-Curunir]

The very next line of Matt's blog post explains this:

> I mean, it’s not impossible to unroll loops (if you know the maximum number of iterations), but the resulting circuit is not likely to be practical. Moreover, this isn’t purely an issue with the use of circuits, but rather with the use of encrypted data. No matter what computational model you employ, you’re always going to have difficulty with things like control flow changes that depend on input data that the executing party can’t see.

If you want to add in interaction, then you have other far more efficient schemes for achieving such FHE, like garbled circuits